Troubleshooting DTMF over PSTN

Unanswered Question
Sep 18th, 2009

Hi everyone,

I have an interesting problem. Users in an office of mine are reporting that they're not able to use any services that require DTMF entires....such as Banks, outside Conference services, etc.

For example...a user calls a conference service and has to enter an ID. He enters 4976962, however the service gives an error and says it heard 9769662.

What's the best way to begin troubleshooting this?


I have this problem too.
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testeven Fri, 09/18/2009 - 06:32


Can you please check in your gateway if you have this command under the dial-peer:

dtmf-relay h245-alphanumeric



Nicholas Matthews Fri, 09/18/2009 - 07:35

Hi there,

It looks like you're hitting a bug. There are two in particular I believe are likely:

CSCso87127 - If your gateway is on 12.4(11)T through 12.4(15)T7, or somewhere around 12.4(16) - 12.4(22) you could be hitting this.

CSCsv04751 - If your IP phones are running 8.4.1 or 8.4.1 SR 1.

I would check these first, and upgrade as necessary.



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